A search for the scientific basis for happiness has beaten the tale of the world's most famous tortoise and the history of humans in Britain to be named this year's best science book.

Harvard psychologist Daniel Gilbert received the prestigious Royal Society Prize for Stumbling On Happiness, which questions the idea that any of us know what happiness actually is, never mind how to achieve or maintain it. He received a £10,000 cheque from the Royal Society's president, Martin Rees, at a ceremony in London this evening.

Space scientist Colin Pillinger, who chaired the judges, said picking the winner had been a difficult job: "Stumbling On Happiness is an outstanding and highly readable winner of this year's Royal Society Prize for Science Books. Daniel Gilbert's voice provides a witty companion throughout this exploration of the science behind the pursuit of happiness - an issue which fascinates us all. He uses cognitive science and psychology to provide intriguing insights into human nature, helping us to understand why we make the decisions we do."

"This was a very easy book to read - lots of humour. One of the members of the committee said that when you were reading this book, it felt like you actually had the author with you in the room."

Other shortlisted books included Homo Britannicus by palaeontologist Chris Stringer of the Natural History Museum: an epic tale of humans on the British Isles, starting when the very first turned up more than 700,000 years ago.

Nobel laureate Eric Kandel's book, In Search of Mind, knitted together behavioural and cognitive psychology, neuroscience and molecular biology to give an insight into the emerging field of the science that studies how the mind works.

An early favourite for the prize had been Lonesome George by Henry Nicholls, which tells the story of a 90kg, 80-year-old tortoise on the island of Pinta in the Galapagos. He is thought to be the sole remaining survivor of his species and scientists have spent decades trying to find ways of reproducing him in a bid to save his kind from extinction.